Thursday, March 28, 2019
Comparing the Enthalpy Changes of Combustion of Different Alcohols :: Enthalpy
Comparing the Enthalpy Changes of Combustion of unalike AlcoholsAimI pass on find the atomic number 1 revision of flame of a number of alcoholsso that I can investigate how and why total heat change is affected bymolecular structure of the alcohol. draughtI impart use Methanol, Ethanol, Propanol and Butanol in the experiment.I impart use these four because they should give me clear results, andthey range from get around chained to long-chained hydrocarbons, sopatterns should be easy to spot in the conclusion.VariablesMy breakaway variables argon- The type of alcohol (I will use ethanol, methanol, propanol and butanol)My pendant variables are- the specific heating capacity of piss- cumulation of water in grams- Change in temperature of waterMy control variables are- The change in temperature of water- 20..C- The mass of water. If this were changed then all the results would be wrong, because it would take diametric amounts of energy to heat different volumes of water- The distance from the bottom of the calorimeter to the cabbage of the wick. Otherwise different amounts of energy could escape individually time reservation it an unfair test.PlanFrom carrying out the follow experiment I will be able to find out theenthalpy change of each fuel I am testing. The enthalpy change ofcombustion of a fuel is the measure of energy transferred when onemole of fuel burn down completely. I will use the fact that 42 Joules ofenergy are required to raise the temperature of 1 gram of water by 1C. Enthalpy change varies according to the following conditions temperature, pressure and concentration of solutions. wherefore I willuse a standard pressure of I atmosphere, a standard concentration of 1mol dm.3 and in conclusion a specified temperature of. I will use theequation enthalpy change = cm..Tc- Specific heating capacity of waterm- Mass of water in gramsT- Change in temperature of waterI will then compare the enthalpy changes and the types of moleculars tructures and so I will able to out why enthalpy change is affectedby the molecular structure of the alcoholPredictionI predict that as the number of carbons in the alcohol is increased,the enthalpy of combustion also increases. The enthalpy change ofcombustion of alcohols increases as the space of the chain increases.This can be explained if we compare one alcohol with the next in theseries. The chain length increases with an addition of a CH2 group.When the alcohol is combusted what actually happens is the covalentbonds are broken, and current bond are formed.